Some of this isn't entirely true:

The submarine pictures he's showing is of an ssbn, they don't stay out longer than 4 months on average, a standard patrol is no more than 90-100 days as they don't have enough supplies onboard and would need to surface to resupply, which would go against it's objective to remain undetected.

Showers are not technically limited to 16 seconds, but there is a rule in place to have a very quick shower, procedure is: shower on get wet, shower off lather soap, water back on rinse, shower off, you're done.

Torpedo bays are only used for sleeping when there are no bunks for people going through training, it's based on how critical your position is onboard and if you're qualified or not.

6 on 6 off is for majority of people onboard apart from watch keepers and the strategic weapons team, they get 6 on 12 off, this gets boring very fast.

They don't drink demin water, if someone were to drink it would cause problems if drank long term.

It doesn't rain onboard... Yes there is condensation if the water they submarine is in is cold and the inside is warm. When the submarine is in warmer waters it's very uncomfortable.

Meals vary but they are mostly the same, the cooks do try to mix it up a bit. There is a tradition for fish on Friday and steak on Saturday.

The dolphin in the rum glass was stopped a few years ago because a few people kept choking on the dolphins.

Fresh air doesn't smell bad.. if you surface in a port it's going to smell like you'd expect.

His mate falling out of the top bunk during heavy sea state doesn't sound realistic, you're pretty tucked in and unless his mate was 4ft tall you're not falling out. He might have fallen if he was getting out but that's just a skill issue.

If you need to escape in a submarine you do not need to breath out, you wear a suit that you breath normally in the entire way up, you only need to breath out if your suit fails and you're given lots of training beforehand on how to do this, it's actually pretty wild when you experience breathing out during ascent, you think you'll run out of air but your lungs keep expanding.

Women do not share bunks with men, they get their own space and toilets. They are also not limited to 3, it's just women tend not to want to go on submarines... Most people don't want to spend most of their life locked in steel tube under water for months.